I am playing around with geometry shaders on my Mac with an Nvidia 9400M graphics card, and at first everything seemed fine. But then I tried merging the new shader program with some existing code, and found that I can no longer send varying variables between the vertex and fragment shaders, only between the geometry and fragment shaders.

In a test shader with one varying float called a which is written in the vertex shader, and read in the fragment shader, I get the following error:

I am playing around with geometry shaders … I tried merging the new shader program with some existing code, and found that I can no longer send varying variables between the vertex and fragment shaders, only between the geometry and fragment shaders.